2. Combine the onion, jalapeno, 1/2 teaspoon salt, and oil in a large saucepan. cover and cook over medium-low heat, stirring often, until the onions and peppers have softened, 8-10 minutes. Stir in the garlic, chili powder, cumin, and sugar, and cook until fragrant, less than 30 seconds. Stir in the tomato sauce, water, and chopped tomato. Bring to a simmer, and cook until slightly thickened, 5 minutes.

3. Nestle the chicken into the sauce. Reduce heat to low, cover, and cook until chicken is cooked through (thickest part reaches 160 degrees), about 12-20 minutes. Transfer the chicken to a plate, and set aside to cool.

4. Strain the sauce through a strainer into a medium bowl, pressing the onion mixture to extract as much liquid as possible. Transfer the onions to a large bowl and set aside. Season sauce with additional salt and pepper to taste.

5. Shred the chicken into bite-sized pieces. Add to the onion mixture, and add 1/4 cup of the enchilada sauce, 1 cup cheese, and the cilantro. Toss to combine.

6. Stack the tortillas on a plate and cover with plastic wrap; Microwave on high until warm and pliable, 40-60 seconds. Spread the tortillas on a clean work surface, and spoon 1/3 cup of the chicken mixture evenly down the center of each. Tightly roll each tortilla and lay seam-side down in a greased 9x13 inch baking dish.

7. Lightly spray the tops of the enchiladas with cooking spray. Place in the oven, uncovered, for about 7 minutes, or until the tortillas start to brown slightly (skip this step if you don't like the crunch).

8. Reduce heat to 400°F. Remove enchiladas and pour sauce evenly on top. Top with the remaining cheese. Cover dish with foil, and bake an additional 20 minutes, or until heated through. Remove foil and bake another 5 minutes, until cheese browns. Remove from oven and let stand 10 minutes before serving. Serve with sour cream, guacamole, salsa, additional cilantro, and as always, enjoy!